Regulator for dynamo-electric machines



(No Model.)

O. P. LOOMIS 8a H. W OOOLEY.

REGULATOR FOB, DYNAMO ELEGTRIG MACHINES. No. 350,754. Patented Oct. 12,1886.

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UNITED STATES PATENT OFFICE.

OSBOR-h P. LOOMIS AND HENRY \V. COOLEY, OF LYNN, MASSACHUSETTS.

REGULATOR FOR DYNAMO-ELECTRlC MACHINES.

SPECIFICATION forming part of Letters Patent No. 350,754, dated October12, 1886.

Application filed December 7, 1885.

T0 aZZ whom it may concern:

Be it known that we, OSBORN P. Looms and HENRY XV. OooLEY, citizens ofthe United States, and residents of Lynn, in the county of Essex andState of Massachusetts, have invented certain new and usefulImprovements in Current Regulation, described, claimed, and shown in thefollowing specification, claims, and drawings.

The invention relates to valuable and patentable features in the form,combination, and disposition of the several elements composing theinvention and necessary to its operation.

Our invention more particularly relates to self-regulating dyuamoscomprising a variable resistance in a shunt.

Its object is to so locate this shuntand variable resistance that themagnetic field is regu lated through a greater range and very gradually.

Our invention consists in general in placing a variable resistance in ashunt-circuit whose terminals are also the common terminals of'both ofthe coils oftheficldmagnets of a dynamo-electric generator.

In order to illustrate the practical manner of carrying out theinvention, drawingsare hereunto annexed and described, in which similarletters of reference represent corresponding elements, and in which eachpart referred to is designated by a single letter.

Figure 1 shows the invention in general, while Fig. 2 shows amodification.

The device embodying means for generating and regulating electriccurrents consists of the combination of field-magnets A and A, a main orworking circuit, B, solenoids O in said circuit, a shunt circuit, D, tothe field magnet A, a helical coil, E, in said shunt-circuit, a bath, F,of mercury located beneath said coils and in. circuit with one or moreof said coils, a pivoted support, H, for said coils, and gear ingconsisting of levers I and 1, connecting said support to the cores J ofsaid solenoids.

Some of the details of construction are as follows: The support forthecoils in practice is at a slighter angle than represented in thedrawings, for the purpose of necessitating as little movement of thecores J as possible. The cores are preferably made of German-sil- (Nomodel.)

ver wire on account of its high specific resistance, and the said wire,of course, should be bare. The terminals of the shunt-circuit aroundfield-magnet A are at K and K, which points are the common terminals ofthe two fieldmagnets A and A. A retractile spring, L, is provided forthe pivoted support.

The modas opermzdi of the device is as follows: hen the resistance ofthe external or working circuit increases, the magnetic field tends todiminish; but the solenoids, thereby receiving less current, allow thepivoted support to rise. In turn, more turns of the coil are thrown intothe shunt-circuit, thereby increasing the resistance of the shunt.Consequently more current passes through the fieldmagnets and theworking-circuit.

The invention is not limited to the pre cise construction hereinbeforedescribed and shown, asit is evident that many Il'lOdifiCtttlOllS may bemade therein without departing from the spirit of the invention. Forinstance, the variable resistance may be modified as shown in Fig. 2.There are a series of resistancecoils, each having terminals mountedupon a pivoted support, which is geared to the solenoidcores. A bath ofmercury is provided beneath the terminals. The circuit which correspondsto the shunt-circuit D may be varied by varying the inclination of thesupport. A dash-pot, N, may be provided to the support, for serving theusual purposes of that article.

By shunting the two opposite arms of the field-magnets of adynamo-electric machine the decrease of the electro-motive force is verygradual and not sudden-an effect to be taken advantage of in theconstruction of the shunting apparatus. Another advantage in this modeof arrangement is that the electro-motive force at the two terminals ofthe two arms of the said magnets is one-half the electro-iuotive forceof the terminals of the four field-magnets according to the formula E:'G R.

Having now stated the object of the said invention, having described itspractical realization by reference to the accompanying drawings, andhaving particularly ascertained the manner in which the same operates toacconr plish the said object, what we consider to be novel and original,and therefore claim as our invention, secured to us by thehereinbeforein-part-recited application for Letters Patent of the UnitedStates, is--- 1. In a dynamo-electric generator, the combination offield-magnets and a variable resistance located in a shunt to one ofsaid fieldmagnets, substantially as and for the purpose specified.

2. In a'dynamoelectric machine, the conibination of field-magnets, amain or working circuit, solenoids in said circuit, a shunt-circuit toone of said field-magnets, a helical coil in said shunt-circuit, a bathof mercury located beneath said coils and in circuit with. one or moreof said coils, a pivoted support I 5 for said coils, and gearingconnecting said support and the cores of said. solenoids, substantiallyas and for the purpose set forth.

Intestimony whereof we hereby sign our names, in the presence of twosubscribing wit- 2o nesses, this 24th day of November, 1885.

OSBORN P. LOOMIS. HENRY W. COOLEY. Witnesses:

* GEORGE D. BANOROFT,

AUSTIN E. RICHARDSON.

